THPS is a kind of environmental anti-microbial reagent. THPS's characterized by THPS's low solidity point and fine stability. THPS can be reserved for long time and can easily dissolve in water. THPS's a kind of new environmental pesticide with high efficacy, low toxicity and low rudimental. THPS can kill germ and aquatic plants. In 1995, the EPA of the United States ratified it with zero toxicity and awarded it with US Green Chemical prize.Tetrakis(Hydroxymethyl)Phosphonium Sulfate (THPS) is a clear straw colored liquid that is between 75-77% pure. THPS is primarily used as a flame retardant additive and can also be used as a fungicide. Tetrakis(Hydroxymethyl)Phosphonium Sulfate (THPS) is recommended for use in cotton, leather, and polyester products.

Tetrakis(hydroxymethyl) Phosphonium Sulfate, commonly referred to as THPS, is used in oilfield application worldwide as a biocide. THPS has been reported to have compatibility concerns with oxygen scavengers, in particular bisulfite (i.e. sodium or ammonium) in these applications. 1,2 The literature has pointed at concerns that the interaction is so severe that when THPS and bisulfite are allowed to react they will generate molecular oxygen (O 2) in situ 1. Upon literature review no mechanistic theory has been proposed to support this view, however several attempts to support the theory via electrochemical oxidation of the phosphorus from a +3 to +5 and the subsequent reduction of the sulfur have been proposed. Further support is attempted by calculating the Gibbs free energy; a negative value would indicate a spontaneous reaction.

THPS biocide is a kind of environmental-friendly water treatment microbiocide which is made of tetrakis(hydroxymethyl)phosphonium sulfate (THPS 75%) solution. THPS can withhold sulfate reducing bacteria (SRB), most of aerobic bacteria including microorganisms that form biofilm in enhanced oil recovery process, production and other supporting systems such as water injection equipments, well water disposal facilities, water holding tanks, recirculating water treatment systems and pipelines. THPS biocide is also effective in controlling microbial growth in drilling muds and stimulation fluids for oil and gas wells. Tetrakis(hydroxymethyl)phosphonium sulfate is characterized by its low solidity point and good stability. THPS 75% solution can easily dissolve in water and can be preserved for a long time. In 1995, the US EPA ratified it with zero toxicity and awarded it with US Green Chemical prize due to THPS's properties of high efficacy, low toxicity and low rudimental. Bichain is one of reliable THPS biocide manufacturers and suppliers of THPS 75, Tetrakis(hydroxymethyl)phosphonium sulfate, THPS 75% solution for oilfield water treatment.

THPS is manufactured in a batch process that involves the chemical reaction of phosphine gas with aqueous formaldehyde in the presence of sulfuric acid and water. THPS exists in equilibrium with tris (hydroxymethyl)phosphine and methylene glycol. Under manufacturing and shipping conditions, the equilibrium strongly favors the formation the formation of THPS.

USES OF THPS [TETRAKIS(HYDROXYMETHYL)PHOSPHONIUM SULFATE]

Tetrakis(hydroxymethyl)phosphonium sulfate is used as a flame retardant in textiles, especially cotton and as a cease and rot resistance agent in fabrics. THPS acts as a biocide against SRB (Sulphate reducing bacteria known as Desulfuvibrio Desulfuricans) which produce enzymes to accelerate the reduction reaction of sulphates to the corrosive hydrogen sulphide and causes corrosion of iron material in a water system. When THPS acts as a corrosion inhibitor in circulating water system.

Mainly used in water treatment systems, oil field operations, and paper-making industry. The advantage is it will soon degrade to a nontoxic substance immediately after use. Also it can be applied to fabric coating as flame retardant, obviously improving flame retarding property.

Water Flooding;
THPS biocide should be added to a water flood system at a point where uniform mixing will occur. First step: add 93 -350 ppm THPS for a noticeably fouled system, when added to a flowing system, slug dose for 2 -6 hours based on flow rates. Repeat as necessary until control is achieved. Second step: Once control has been achieved, add 14 -98 ppm THPS biocide weekly or as needed to maintain control. As for continuous treatment, THPS can be dosed continuously at a level of 14 -67 ppm.

Oil and Gas Production and Transmission Systems and Pipeline;
THPS 75% solution should be added at a point in the pipeline where uniform mixing will occur. The application should be conducted to ensure maximum distribution of product through the internal surface of the pipeline by adding an amount of biocide which eventually comes out the other end of the pipeline. Criteria for success of the treatment will be reduction in bacterial count and/or corrosion rates. Adding step is same as that of water flooding. As for continuous treatment, THPS can be dosed continuously at a level of 14 -100 ppm.

Drilling Muds, Well Completion and Workover Fluids;
THPS biocide should be added to these fluids at a point where uniform mixing will occur. Add 33-1400 ppm of product to a freshly prepared fluid depending on severity of contamination.

Gas Storage Well systemsi;
Individual injection wells should be treated with THPS 75 at the same dosage and same steps as described under water flooding. Injections should be repeated as needed to maintain control. Individual drips should be treated with a sufficient quantity of product to produce a concentration of 33.3 -133.3 ppm when diluted by the water present in the drip. Injections should be repeated as needed to maintain control.